CARLSBAD, Calif., Feb. 27, 2012 /PRNewswire/ -- Radiosurgery with fast dose delivery technology can dramatically reduce the time it takes to complete treatments for spine, brain, and lung cancer, while tumor tracking technology can enhance the precision of prostate cancer treatments, according to leading radiation oncologists who spoke at Varian sponsored workshops during the 2012 Scientific Meeting of The Radiosurgery Society™ (RSS) here last week.
John B. Fiveash, M.D., professor of radiation oncology, and Richard Popple, PhD, associate professor of medical physics at the University of Alabama at Birmingham (UAB), detailed clinical experiences using RapidArc® Radiosurgery on a TrueBeam™ STx system from Varian Medical Systems (NYSE: VAR).
Drawing on their experience planning and delivering some 435 courses of treatment for prostate, head and neck, brain, spine, lung, liver, and pancreatic cancer, Fiveash and Popple described the potential benefits of the High Intensity Mode on TrueBeam STx, which makes it possible to deliver dose more quickly than conventional dose delivery methods, and may reduce the amount of radiation scatter than can reach surrounding healthy tissues during treatment.
"The TrueBeam STx machine allows radiosurgery to be completed in a dramatically short time frame," said Fiveash, who is also the interim associate director for clinical research at the UAB Comprehensive Cancer Center. "In many cases, these procedures can be scheduled to fit into a normal radiotherapy treatment time slot."
The UAB clinicians also detailed their experiences using TrueBeam to deliver RapidArc Radiosurgery, a fast, accurate approach to targeting cancer with carefully shaped high-energy beams during one or more continuous rotations of the treatment machine around the patient. "RapidArc Radiosurgery enables us to deliver a highly conformal dose to a tumor, using multiple partial non-coplanar arcs," Fiveash said, describing an approach to radiosurgery that increases the number of beam angles used, thereby minimizing the dose to surrounding healthy tissues.
Prostate Cancer Treatments Enhanced
In another Varian-sponsored workshop, Constantine A. Mantz, MD, chief medical officer at 21st Century Oncology in Fort Myers, Florida, presented early results from a prospective Phase II study showing that low-risk prostate cancer patients treated with radiosurgery using Calypso® real-time tracking technology had favorable health-related quality of life scores and minimal toxicities. The study examined 84 patients who received treatment between January 2007 and January 2011. Patients received five treatments, on alternating days, each of 8.0 Gray units (a measure of radiation dose). Patients completed a quality of life questionnaire before and after treatment. Follow-up data was collected from patients 3, 6, and 9 months, as well as 1, 2 and 3 years post treatment.
Mantz pointed out that real-time tumor tracking is proving to be an important tool for reducing treatment margins during SBRT for prostate cancer, which is critical in limiting side effects.
"Based on 36 months' worth of follow up data, our prostate cancer trial is showing that real-time tumor tracking with SBRT (a form of radiosurgery targeting tumors in the body) appears to have clinically significant benefits in decreasing acute toxicity, as well as improving quality of life and biochemical outcomes," he said. "The Calypso real time tracking technology enables us to deliver increased doses of radiation accurately to the tumor and minimize exposure of surrounding healthy tissues. These are the fundamental goals when treating prostate cancer."
"Radiosurgery is poised to make a big difference in how cancer is treated," said Tim Guertin, president and CEO of Varian Medical Systems, a major co-sponsor of the meeting, in an address he made during one of the general sessions. "As the technology has advanced, radiosurgery utilization has been steadily rising over the last decade because clinicians are seeing—and publishing about—real benefits to patients."
TrueBeam and RapidArc Scientific Sessions
Varian's TrueBeam machine and RapidArc Radiosurgery were also the focus of two of the meeting's scientific sessions. Corey Zankowski, PhD, vice president of product management at Varian, partnered with Sonia Dieterich, PhD, clinical associate professor and chief of physics at the Department of Radiation Oncology, Stanford University Medical Center, to detail the ways in which Varian's TrueBeam and TrueBeam STx platforms have been optimized for radiosurgical procedures. In a subsequent session, they reviewed the technical and clinical benefits of RapidArc Radiosurgery, summarizing the literature as well as Stanford's clinical experience using this modality to treat brain, spine, lung, gastrointestinal, and genitourinary cancer.
"The applications, technologies, and methodologies in the field of radiosurgery have been developing rapidly over the last ten years," said Kolleen Kennedy, president of Varian's Oncology Systems business. "We commend The Radiosurgery Society for its efforts to meet the need for continual learning in this field. The Society put together a stellar and comprehensive program with world-class clinical thought leaders who presented on a wide spectrum of topics over a period of three days. Varian was pleased to be the leading sponsor of this important meeting."
About Varian Medical Systems
Varian Medical Systems, Inc., of Palo Alto, California, is the world's leading manufacturer of medical devices and software for treating cancer and other medical conditions with radiotherapy, radiosurgery, and brachytherapy. The company supplies informatics software for managing comprehensive cancer clinics, radiotherapy centers and medical oncology practices. Varian is a premier supplier of tubes and digital detectors for X-ray imaging in medical, scientific, and industrial applications and also supplies X-ray imaging products for cargo screening and industrial inspection. Varian Medical Systems employs approximately 5,900 people who are located at manufacturing sites in North America, Europe, and China and approximately 70 sales and support offices around the world. For more information, visit http://www.varian.com or follow us on Twitter.
 C.A. Mantz et al. A Phase II Trial of Real-time Target Tracking SBRT for Low-Risk Prostate Cancer Utilizing the Calypso 4D Localization System: Patient Reported Health-related Quality of Life and Toxicity Outcomes. Int J Radiat Oncol Biol Phys. (Nov 2010) Vol. 78, Issue 3, Supplement, S57-S58.
 Pan, et al. Cancer. Volume 117, Issue 19 (2011): 4566-4572
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SOURCE Varian Medical Systems